Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of this study was an evaluation of the prevalence of myopathies in paediatric patients scheduled for orthopaedic surgery (clubfoot) performed under regional anaesthesia. Seventeen infants scheduled for lower limb orthopaedic surgery were studied to verify coexisting neuromuscular disorders with electromyography and muscle biopsy during surgery. All surgical procedures were performed under caudal block or spinal anaesthesia, associated with light general anaesthesia. No major cardiorespiratory, neurological or malignant hyperthermic complications (muscle rigidity, arrhythmias, hyperpyrexia) were observed. Combined neurological, electromyographic and biopsy studies showed a high rate of myopathic changes (70%). Performance of clubfoot surgery under light general anaesthesia with regional techniques was free from any problems. The high rate of myopathic changes (70%) observed in the muscle biopsies suggests that precautions should be taken with paediatric patients for clubfoot surgery and a regional anaesthesia technique with adequate monitoring may be helpful to prevent possible malignant hyperthermia related problems.
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PMID:Prevalence of unsuspected myopathy in infants presenting for clubfoot surgery. 748 36

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle. In humans, MH is inherited in an autosomal dominant fashion; in swine, the principal model for MH, it is in a recessive fashion. Those with MH susceptibility usually are asymptomatic except in the presence of certain "triggering" anaesthetic agents such as isoflurane, enflurane and the muscle relaxant succinylcholine. Upon such exposure hypermetabolism, increased CO2 production, acidosis, muscle rigidity, rhabdomyolysis and hyperthermia occur. Untreated, death may result in 70% of patients. With prompt diagnosis and treatment with dantrolene sodium, the mortality is less than 10%. The overall incidence of MH is low (perhaps 1:50,000 anaesthetics), but it is more common in children. Children also display a paradoxical increase in jaw muscle tone to succinylcholine which often presages MH, but confusing clinically, may also be a normal response to succinylcholine. The pathophysiology of MH centres around a defect in calcium flux in skeletal muscle. A specific base pair change in the gene that codes for the ryanodine receptor calcium channel in muscle has been demonstrated in susceptible swine, but occurs rarely in humans. It is hoped that the understanding of the molecular genetics of MH will lead to a simpler diagnostic test than is currently available, and enhance our understanding of MH and its relation to other myopathies.
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PMID:An update on the malignant hyperthermia syndrome. 771 Feb 42

Malignant hyperthermia (MH) susceptibility remains the commonest cause of death owing to general anaesthesia. In humans, genetically predisposed to MH, anaesthesia can induce skeletal muscle rigidity, hypermetabolism and hyperthermia, which if not immediately reversed can lead to tissue injury and death. In swine, the corresponding condition leads to stress-induced deaths and devalued meat products. Aberrant behaviour in the calcium (Ca2+) release channel (the ryanodine receptor) of skeletal muscle sarcoplasmic reticulum has been implicated in the cause of both the porcine and human syndromes by biochemical, physiological and molecular genetic analysis. In swine, a single mutation in the ryanodine receptor gene (RYR1) can account for all cases of MH in all breeds, but a series of different RYR1 mutation are uncovered in human families with MH. In addition, the lack of linkage between MH and RYR1 in some families indicates a heterogeneous genetic basis for the human MH.
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PMID:The genetic basis of malignant hyperthermia. 797 21

Malignant hyperthermia (MH), an inherited neuromuscular disease triggered by halogenated inhalational anaesthetics and skeletal-muscle relaxants, appears to be due to an alteration of intracellular Ca2+ homoeostasis. MH occurs in 1 out of 20,000 anaesthetized adults and is characterized by hypermetabolism, skeletal-muscle rigidity and elevation in body temperature, which is frequently fatal [MacLennan and Phillips (1992) Science 256, 789-794]. The defect responsible for the disease may lie within the mechanism controlling the release of Ca2+ from sarcoplasmic reticulum via the ryanodine-receptor (RYR) Ca2+ channel; in fact a point mutation in the RYR has been associated with MH in some human families, as well as in the MH-susceptible pig. To date, however, no direct evidence has been obtained demonstrating that the point mutation is both necessary and sufficient to cause functional alterations in RYR-mediated Ca2+ release. In the present report we show that the presence of the Arg-to-Cys point mutation in the recombinant RYR expressed in COS-7 transfected cells causes abnormal cytosolic Ca2+ transients in response to 4-chloro-m-cresol, an agent capable of eliciting in vitro contracture of MH-susceptible muscles.
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PMID:Alteration of intracellular Ca2+ transients in COS-7 cells transfected with the cDNA encoding skeletal-muscle ryanodine receptor carrying a mutation associated with malignant hyperthermia. 805 91

We describe a case of generalized muscle rigidity in a 2-year-old patient with Freeman-Sheldon syndrome undergoing surgery for eventration of the diaphragm after anesthetic induction with halothane and succinylcholine. Anesthetic induction was by mask with oxygen, nitrous oxide and halothane, with succinylcholine as a muscle relaxant. Approximately 10 minutes after start of induction, muscular rigidity appeared and developed rapidly, becoming severe and compromising ventilation. Tracheal intubation was attempted without success, owing to stiffness of the masseter muscles. Sodium dantrolene 2.5 mg/kg was administered and relaxation was achieved immediately for both masseter and peripheral muscles, such that the patient recovered spontaneous breathing. We conclude that there is risk of association between Freeman-Sheldon syndrome and malignant hyperthermia.
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PMID:[Freeman-Sheldon syndrome: generalized muscular rigidity after anesthetic induction]. 805 48

A young man underwent anaesthesia and surgery after multiple fractures. After 2 hours of anaesthesia, the patient developed hypercapnia, acidosis, hyperpyrexia and mild muscle rigidity. He was treated for malignant hyperthermia. Muscle tension studies with caffeine-halothane and muscle histology proved normal. The differential diagnosis of this abnormal metabolic response is briefly discussed.
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PMID:A hypermetabolic reaction during anaesthesia and surgery. A case report. 821 15

A patient was admitted with hyperthermia, muscle rigidity, rhabdomyolysis and disseminated intravascular coagulation. He was initially thought to have taken 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy'), but subsequent toxicology revealed the presence of 3,4-methylenedioxyethamphetamine (MDEA, 'Eve'), its sister drug, in his blood. Subsequent in vitro testing for malignant hyperthermia proved to be negative.
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PMID:Hyperthermia associated with 3,4-methylenedioxyethamphetamine ('Eve'). 832 92

We experienced a case of abortive malignant hyperthermia during funnel chest surgery. Although a 5-year-old boy had muscle rigidity after the intravenous injection of succinylcholine chloride, the tracheal intubation was easy. The boy had high body temperature, metabolic acidosis, hyperkalemia and myoglobinuria during nitrous oxide-oxygen-sevoflurane anesthesia. We immediately came to the diagnosis of abortive malignant hyperthermia, gave intravenous injection of dantrolene sodium and started body surface cooling. Postoperative course was uneventful. It is necessary to pay a particular attention to possible malignant hyperthermia in patients with funnel chest surgery.
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PMID:[A case of abortive malignant hyperthermia during funnel chest surgery]. 835 Apr 73

We have examined the phenotypic expression of several parameters associated with malignant hyperthermia (MH) susceptibility in three groups (homozygous normal, homozygous abnormal and heterozygous) of Yorkshire/Duroc swine genotyped by a mutation in the ryanodine receptor. Subgroups of homozygous abnormals were classified further by the appearance or absence of muscle rigidity on prolonged in vivo challenge with halothane and suxamethonium. Four swine heterozygous for the proposed MH mutation were indistinguishable from five homozygous normal swine in temperature, heart rate, lactate concentrations, base excess and pH determined during the prolonged halothane and suxamethonium challenge. Resting creatine kinase concentrations, the in vivo barnyard challenge, the in vitro contracture response of skeletal muscle to 3% halothane and the threshold for Ca(2+)-induced Ca2+ release were also similar for subgroups of homozygous normals and heterozygotes. Therefore, inheritance of only one allele carrying the defect in the ryanodine receptor does not significantly alter phenotypes associated with MH susceptibility in this strain of swine. As four swine homozygous for the proposed MH defect did not exhibit rigidity and three of these had no other signs of MH on prolonged halothane and suxamethonium challenge, we conclude that the reported mutation in the ryanodine receptor may be necessary, but is not sufficient, for consistently eliciting the malignant hyperthermia syndrome. These findings suggest that a modulator of the syndrome may explain variability within individuals in human MH.
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PMID:Phenotypes associated with malignant hyperthermia susceptibility in swine genotyped as homozygous or heterozygous for the ryanodine receptor mutation. 839 25

This clinical case report describes the use of extremely high doses of dantrolene in the management of an episode of malignant hyperthermia (MH). A 6-year-old, 25 kg girl underwent anesthetic induction with halothane for an elective inguinal herniorrhaphy. Tachydysrhythmias, laryngospasm, opisthotonos, rhabdomyolysis, and profound metabolic acidosis ensued as features of an MH crisis. Initial dantrolene administration did not alleviate the symptoms. Increasing doses of dantrolene eventually totaling 42 mg/kg, along with symptomatic supportive care, were administered successfully to treat the event. It is postulated that the severe muscle rigidity may have precluded the circulation of dantrolene to its site of action. The role of the Malignant Hyperthermia Association of the United States (MHAUS) Hotline as a 24-hour consultative service is noted.
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PMID:Successful treatment of an episode of malignant hyperthermia using a large dose of dantrolene. 844 73


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